Fermion emission saturates Pauli bound in Nariai black holes
In the two-horizon throat, the mean fermion number approaches exactly 1, so no quantum superradiance can occur.
· “Saturation of Pauli blocking in near-extremal charged Nariai black holes”
gr-qc
General Relativity and Quantum Cosmology
General Relativity and Quantum Cosmology Areas of gravitational physics, including experiments and observations related to the detection and interpretation of gravitational waves, experimental tests of gravitational theories, computational general relativity, relativistic astrophysics, solutions to Einstein's equations and their properties, alternative theories of gravity, classical and quantum cosmology, and quantum gravity.
sort pith recommended most recent
Redshift of an orbiting star can fingerprint a black hole's accretion
Ordinary inflow shrinks orbits and boosts redshift swings; phantom-like fluid does the opposite.
· “Test particle motion around a black hole dressed with a spherically symmetric stationary fluid”
New Hamiltonians capture all orders of spin in black hole binaries
A tracelessness condition singles out Kerr geometry and exponentiates the key gravitational amplitudes.
Flat string universes almost always break effective field theory
Only negative curvature or two fine-tuned limits escape; prolonged acceleration gets a Trans-Planckian-style bound.
· “A species scale-driven breakdown of effective field theory in time-dependent string backgrounds”
Radiation reaction fixes the G^4 angular momentum loss
A closed form now resums every half-odd post-Newtonian correction at arbitrary velocity.
· “Radiation-Reaction and Angular Momentum Loss at mathcal{O}(G⁴)”
Quantum fields on a fixed black hole yield its temperature and entropy
One derivation gives T=1/8πGM and S=A/4G, tying gravity to thermodynamics.
Method puts four-loop gravity integral into canonical form
Despite apparent singularities, this Calabi-Yau integral admits ε-factorized form.
· “Calabi-Yau Feynman integrals in gravity: varepsilon-factorized form for apparent singularities”
Penrose limits turn hidden black hole symmetries into isometries
Photon-ring and highly damped overtones both descend from one seed mode via pp-wave symmetries.
· “pp-Waves and the Hidden Symmetries of Black Hole Quasinormal Modes”
Smooth condensate flows realize sonic black holes and wormholes
In 2D condensates, flow can outrun sound at a horizon, with a computable Hawking temperature for uniform-density setups.
· “Acoustic black holes, white holes, and wormholes in Bose-Einstein condensates in two dimensions”
Charged pulsar models pass every stability and viability test
Nine real pulsars check out — energy bounds, equilibrium, causality, and collapse resistance all hold.
· “Exploring the viability of charged Spheres admitting non-metricity and matter source”
Gravity has a conserved enstrophy that pushes waves to low frequencies
A curvature functional acts like 2D fluid enstrophy, pushing wave energy to lower frequencies when damping is weak.
· “Gravitational Enstrophy: Local Geometric Origin and Inverse-Cascade Constraints”
One ratio can test if gravitational waves are truly classical
Click statistics and phase noise in bar detectors separate coherent from thermal and squeezed gravitational waves.
Dust PBHs: an initial neck always makes a bifurcating horizon
When pressure is absent, necks in the initial data are exactly where future and past horizons meet.
Stacked cluster caustics cap modified-gravity strength at 4e-6
Outer-region escape-velocity profiles of 122 clusters, with no X-ray or lensing data, set |f_R0| ≤ 4.4×10⁻⁶.
· “Outer regions of galaxy clusters as a new probe to test modifications to gravity”
Chen-Teo metrics end the Euclidean black hole uniqueness conjecture
Complete Ricci-flat manifolds that look flat at infinity yet are not Euclidean Kerr black holes.
Standard cosmology excluded at 4σ by newest data
Modified gravity and dynamical dark energy both fit Pantheon+ and DESI observations far better than ΛCDM.
· “Modified gravity/Dynamical Dark Energy vs ΛCDM: is the game over?”
Three horizons emerge from two symmetry-breaking coefficients
First-order corrections to Schwarzschild shift horizons, Hawking temperature, and periastron precession.
· “Perturbative black-hole and horizon solutions in gravity with explicit spacetime-symmetry breaking”
Simulated black-hole mergers reach 1e-12 waveform mismatch
GR-Athena++ runs beat LISA's accuracy bar five orders of magnitude for the (2,2) mode, at one radius only.
· “Binary Black Hole Waveforms from High-Resolution GR-Athena++ Simulations”
LIGO-India at A♯ can replace a 20 km Cosmic Explorer
Modeling shows it localizes 9,000+ neutron-star mergers a year within 10 square degrees.
· “The Critical Role of LIGO-India in the Era of Next-Generation Observatories”
Stability of f(R) gravity mirrors its scalar-tensor dual
For polynomial models, only even powers with positive coefficients pass both stability tests.
· “Does the stability of f(R) theories imply the stability of the dual scalar-tensor theory ?”
Light scalars' wavefunction is a degenerate polytope limit
Flat-space scattering amplitudes sit on higher-codimension faces; the face's codimension gives the pole's order.
· “Cosmological Polytopes and the Wavefuncton of the Universe for Light States”
Analogue black hole radiation is not thermal
Complete mode expansion shows Hawking-partner correlations deviate from a thermal spectrum at finite wavelengths.
· “Departing from thermality of analogue Hawking radiation in a Bose-Einstein condensate”
Self-gravity shrinks length-measurement error to the Planck scale
The larger cubic-root bound would be replaced by a Planck-length floor that does not grow with distance.
· “Salecker-Wigner-Karolyhazy Gedankenexperiment in light of the self-gravity”
Wormhole transit time nearly equals mouth separation
Transit time approaches the mouth separation, beating eternal wormholes by more than a factor of two.
· “Traversable Asymptotically Flat Wormholes with Short Transit Times”
Wormhole in f(R) gravity needs no exotic matter
A power-law shape function yields a viable f(R) model; null, weak, strong, and dominant energy conditions all hold for r ≥ 1.7.
· “Validation of Energy Conditions in Wormhole Geometry within Viable f(R) Gravity”
Quantum vacuum replaces black-hole horizons with wormhole throats
Static spherical spacetimes with horizon-divergent negative vacuum energy get a wormhole throat instead of a horizon.
· “Imprints of quantum vacuum fluctuations on the gravitational field of a spherical mass”
dS-core black holes always break the timelike convergence condition
The Hawking-Penrose theorem is sidestepped because the TCC-only mass condition fails near the core.
· “Timelike convergence condition in regular black-hole spacetimes with (anti-)de Sitter core”
One quartic equation yields dark energy from pure brane geometry
A single Friedmann-type law ties general relativity, DGP, and Gauss-Bonnet brane models together with no exotic matter.
Fluid spin can enlarge or shrink black-hole accretion tori
Co-rotating fluid spin grows the torus; counter-rotating spin shrinks it, and faster for high-spin Kerr holes.
· “Equilibrium models of Weyssenhoff spin fluid accretion tori around Kerr black holes”
Polyperspective state makes relativistic measurement updates consistent
A direct sum of local and joint density operators keeps Bell correlations and charge intact after measurements.
· “State updates and useful qubits in relativistic quantum information”
Weyl-vector gravity reduces to modified Poisson equations
If right, the Bardeen potentials and Weyl vector follow from the matter density alone.
· “Weak Field Limit of the Nonminimally Coupled Weyl Connection Gravity”
Dressed variables dissolve the hole argument for fiber bundles
Rewriting gauge theories in manifestly invariant fields makes the bundle a structural quality of the fields.
· “What Price Fiber Bundle Substantivalism? On How to Avoid Holes in Fibers”
Exotic GW sources now analyzed tenfold faster
RIFT's new adaptive-volume integrator also fixes a waveform frame bug that could bias precessing binaries.
· “Narrowing RIFT: Focused simulation-based-inference for interpreting exceptional GW sources”
Phantom dark energy calls for steeper potentials
A scalar-field coupling to matter turns disfavored stringy exponentials into DESI-compatible fits.
Entropy increase fails in a band just after the quantum bounce
A density-by-density map shows where the second law holds and where negative temperatures restore it.
Sgr A* shadow pins black hole charge near 0.8–0.95
Shadow-size measurements of the Milky Way's central black hole leave only a narrow charge window for this modified-gravity model.
· “Gravitational signatures of a nonlinear electrodynamics in f(R,T) gravity”
Sgr A* shadow sets the best dark halo constraints
A rotating black hole in a dark matter halo matches measured shadow sizes within 1–2 sigma over a wide parameter range.
· “Kerr-like Black Hole Surrounded by Cold Dark Matter Halo: The Shadow Images and EHT Constraints”
Metric-affine gravity is Cartan geometry in disguise
Dressing away gauge translations leaves the frame bundle's Cartan-affine kinematics.
Open universes tame late-time string corrections
The late-time attractor is set by the convex hull of potential exponents, yielding acceleration with small corrections.
Static event horizons can exist in an expanding cosmos
Painlevé–Gullstrand metrics keep the horizon fixed while space expands far away, reducing to Schwarzschild–de Sitter when H is constant.
Hawking-like horizon flux drives cosmic expansion
A curvature-coupled source term Q = αH^3 replaces Λ and flattens space without inflation.
· “Horizon-Driven Expansion from Hawking-Like Radiation: A Curvature-Coupled Cosmological Model”
Gravitational-wave forest at Milky Way's core could cover LISA's band
Steady swarms of black-hole and brown-dwarf inspirals at Sgr A* could obscure LISA's key target signals.
One year of next-gen detectors exposes the first stars' demographics
Simulated next-gen detector data separates Population III from ordinary black-hole mergers and recovers its IMF.
Gravity and its dual are quantum-inequivalent in even dimensions
A twisted Euler characteristic fixes the mismatch; odd dimensions stay equivalent, and four dimensions gain a modular S-duality.
Infalling plasma can stamp 8% polarization on black-hole X-rays
Photons boosted by free-fall inside the ISCO can outshine the disk's thermal polarization signal for edge-on views.
gwharmone reproduces eccentric merger harmonics in 0.1 seconds
A 0.1-second evaluation makes eccentric mergers practical for searches and parameter estimation.
Dark energy from black hole formation fits late-universe data
A model without a cosmological constant fits supernova, BAO, and chronometer data just as well as ΛCDM.
· “Observational implications of Wald-Gauss-Bonnet topological dark energy”
Cosmic distance-duality law holds to redshift 2.3
A lensing-and-supernova fit finds the CDDR violation parameter consistent with zero, without assuming an expansion history.
· “Model-Independent Probe of Cosmic Distance Duality Relation”
Barrow's rough horizons stretch black hole lifetimes
Nonzero fractal index Delta makes Hawking-evaporation time grow as M0^{3(1+Delta)} instead of M0^3.
Cheap waveforms mimic supernova signals closely enough for AI training
New generator adds polarization and multiple oscillation modes, so detection pipelines can train on thousands of realistic signals.
· “Phenomenological gravitational waveforms for core-collapse supernovae”
Third-order gravitational waves outgrow second-order from inflation
New loop calculation finds detectable scalar-induced GWs from inflation may not be perturbatively calculable.
· “Spectrum of third-order tensor perturbations induced by excited scalar fields”
A delayed electroweak phase transition can form black holes
A vacuum-energy timescale, not density contrast, best predicts collapse; new-model search regions are updated.
Kalb-Ramond black hole passes solar tests only if parameters are tiny
Four solar-system tests force the new terms between 10^-9 and 10^-4.
· “Black hole with global monopole charge in self-interacting Kalb-Ramond field”
Relative entropy reproduces the black-hole area law
For large Schwarzschild radius, the entropy scales with horizon area as S ≈ C A/4G.
· “The quantum relative entropy of the Schwarzschild black-hole and the area law”
Inflation's gravitons break down late-time perturbation theory
Secular logarithms from graviton production grow every e-fold; two resummation methods combined resum both.
Triplet coupling explains magnetar QPO flicker and drift
A three-mode resonance, not independent ringing modes, drives QPOs' reappearance and frequency drift.
MOG parameter shifts periodic-orbit energy in both directions
If confirmed, future space-based GW detectors could measure the MOG parameter from EMRI signals.
· “Periodic orbits and their gravitational wave radiations around the Schwarzschild-MOG black hole”
Curved space shrinks and reddens the blackbody spectrum
A circle-based model of blackbody radiation predicts dimmer, narrower, redshifted spectra as curvature grows.
21-cm forest could weigh neutrinos down to 0.1 eV
Early-universe absorption lines would rival the Ly-alpha forest and test neutrino mass hierarchy.
Analytic formulas cover every impact parameter in black hole images
Shell and ring images now render from one closed formula, exposing a bright rim outside infalling flows.
Black hole thermodynamics survives an extreme triple-scaling limit
Planck's constant goes to infinity while c and G_N vanish, yet temperature, entropy, and energy stay finite.
New twist cuts waveform mismatch for precessing black holes
Numerical spin-precession angles improve faithfulness to numerical relativity with only a 1.2x slowdown.
· “Fast frequency-domain gravitational waveforms for precessing binaries with a new twist”
Blue-tilted early universe doubles dark matter clumps
Zoom-in simulations of Milky Way-mass halos show four times more low-speed subhalos and denser inner structures.
Sub-1% waveform matches for eccentric black-hole binaries
A new multipolar model improves on earlier eccentric templates by about an order of magnitude across 20-200 solar masses.
Quasar-triggering mergers can produce the pulsar-timing background
A census of bright quasars, converted into black-hole merger rates, matches the measured gravitational-wave background.
A wall outside the horizon reproduces random-matrix chaos
Scalar and fermion modes near the BTZ horizon show Wigner-Dyson spacing, a linear ramp, and Krylov peaks.
· “Brickwall One-Loop Determinant: Spectral Statistics & Krylov Complexity”
One equation fixes extremal black-hole masses
Adding an axion lets long-range force and binding energy disagree for dyonic hole pairs.
Semi-coherent search finds all five LISA black-hole binaries
The five recovered signals have injected signal-to-noise ratios of 12.94 or higher, pointing to a lower LISA detection threshold.
· “Searching for stellar-origin binary black holes in LISA Data Challenge 1b: Yorsh”
Entropy of a tilted Dirac cone matches black-hole entropy
With a spatial tilt gradient and tuned temperature, the material's entropy scales linearly in T just like a 2+1-D black hole.
· “Smart Holes: Analogue black holes with the right temperature and entropy”
Semigroup expansion makes kinematical superalgebras non-degenerate
Three-dimensional Chern-Simons actions built on them then have curvature-free field equations.
· “Non-Lorentzian Supergravity and Kinematical Superalgebras”
LISA could probe quantum black-hole deformation to 1 in 1,000
One year of EMRI data could beat black-hole shadow bounds by two orders of magnitude.
· “Constraining polymerized black holes with quasi-circular extreme mass-ratio inspirals”
Viscous relativistic fluids get a well-posed theory
A single transport inequality suffices for strong hyperbolicity, so simulations can trust the continuum evolution.
One formula captures pole-to-branch-cut transition at T=0
An explicit analytic series for the charged scalar correlator, with QNM dispersions and superconducting Tc.
· “Exact low-temperature Green's functions in AdS/CFT: From Heun to confluent Heun”
Memory-burdened black holes may explain the PTA signal
Slowed black-hole evaporation reconciles inflationary gravitational waves with all bounds and predicts a kHz signal.
Hyperfluids reshape cosmology while keeping GR's solution forms
A metric-affine study shows spin and shear enter as modified effective equations of state.
Finely tuned anomalyon can seed all dark matter as black holes
The anomalyon's blue short-scale spectrum leaves CMB predictions intact while forming PBHs at smaller scales.
· “Inflation with the Trace Anomaly Action and Primordial Black Holes”
Brane tensions in de Sitter obey new Festina Lente bounds
The constraints, derived from Nariai black-hole stability, are satisfied by all Type II D-branes in the weak-coupling limit.
· “De Sitter space constraints on brane tensions and couplings”
Glitch masking returns galactic binaries to clean-data accuracy
Glitch masking restores galactic-binary frequencies to 1 ppm; planned gaps still widen black-hole error bars 2-3x.
· “Extraction of gravitational wave signals from LISA data in the presence of artifacts”
Photon ring switches from shrink to grow with temperature
Holographic images tie the ring radius to chemical potential and a gravity parameter, offering a new probe of modified gravity.
· “Holographic images of a charged black hole in Lorentz symmetry breaking massive gravity”
Photon rings survive overcharging up to q/m=1.178
Light-ring topology fixes the allowed non-commutative range and picks a Born-Infeld AdS black hole for Weak Gravity Conjecture tests.
